drm/i915: Enable/disable the dithering for LVDS based on VBT setting
Enable/disable the dithering for LVDS based on VBT setting. On the 965/g4x
platform the dithering flag is defined in LVDS register. And on the ironlake
the dithering flag is defined in pipeconf register.
Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 84705b7..0c9b79f 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3195,7 +3195,20 @@
* appropriately here, but we need to look more thoroughly into how
* panels behave in the two modes.
*/
-
+ /* set the dithering flag */
+ if (IS_I965G(dev)) {
+ if (dev_priv->lvds_dither) {
+ if (IS_IRONLAKE(dev))
+ pipeconf |= PIPE_ENABLE_DITHER;
+ else
+ lvds |= LVDS_ENABLE_DITHER;
+ } else {
+ if (IS_IRONLAKE(dev))
+ pipeconf &= ~PIPE_ENABLE_DITHER;
+ else
+ lvds &= ~LVDS_ENABLE_DITHER;
+ }
+ }
I915_WRITE(lvds_reg, lvds);
I915_READ(lvds_reg);
}